I. Field of the Invention
This invention relates to hand held signaling device used to signals over wide distances. More particular, the invention relates to a portable electrical horn having an improved safety, portability, reliability, and an increased power source storage capacity.
II. Related Prior Art
Horns are widely used, among others, in sporting, hunting, and rescue operations. Typically, horns are divided in two distinct types: air horn and electrical sirens.
Hand-held air horn devices operate with use of a compressed gas released from a high-pressure canister (the gases) may be compressed air, butane, Hydro Fluoro Carbon (HFC) 134 A gas (Environmentally Safe Freon), Freon® 22 as an HCFC refrigerant, and any other type of compressed gas combinations (Nitrogen, Argon, etc.) (collectively each of these conventional gasses and gas compositions/mixtures are referred to as either “gas” or “air” as discussed hereafter).
Air horns of this type normally have an acoustically required trumpet-type fixture which operates in concert with an actuator button and a cone-shaped trumpet nozzle which is configured to produce a loud horn blast when air is released from the canister and through the trumpet fixture and outwardly from the conical trumpet nozzle.
Hand-held air horns have typically a limited capacity since the dimensions of the canister are critical to the horn's portability. A configuration of an air horn device is rather complicated due to numerous mechanical components including, among others, the above-mentioned canister, trumpet nozzle and the required and associated seals, but have been historically used for generation of a loud annunciation of some signal.
Specifically, conventional air horn devices should be configured to have excellent sealing characteristics so as to prevent compressed fluid from leaking though the housing of the device, risking functional loss, poisoning, staining, and other detriments noted below. Additionally, the accidental loss of gas pressure renders an air horn non-functional, and the slow loss of pressure (via a slow leak), results in a steadily decreasing audio output.
However, due to the limitations of sealing technology, many known air horn devices may not be satisfactory leak-proof. As a consequence, the condensate formed during the use of an air horn device (from the endothermic transformation from high to low pressure and from a liquid to a gas) may leak through poorly sealed joints and burn the hands of the user where such condensate is super-cold or an irritant to the skin.
Still a further negative consequence of the poorly sealed air horn device relates to the user's hands which may become slippery during the use of the device which, in turn, may negatively affect a grip on the device by the user. Furthermore, used at high altitudes, an air horn device may be health-hazardous due to the expansion of compressed fluid/propellant, which may minimize the effectiveness of the device and, in extreme situations, lead to fire for select gas compositions. Structural countermeasures directed to minimization of the above-discussed problems often lead to an overly complicated structure of the device that may be cost-prohibitive.
Finally, an additional detriment to many conventional gasses involves the problem of unintentional poisoning or accidental oxygen substitution. For example, a case of accidental Freon 22 (monochlorodifluoromethane) poisoning in a fishing vessel has been reported (See report by Koreeda A., Department of Forensic Medicine, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto 860-8556, Japan, Forensic Sci. Int. 2006 Feb. 18.
Electric horns alleviate at least some of the problems associated with the air-type horn device. Typically, electrical horns have traditionally used a vibrating diaphragm driven by an electromagnetic device. Current pulses are developed by a mechanical switch responsive to diaphragm movement such that the switch, being normally closed, would energize a magnetic coil to cause diaphragm movement in one direction against its spring bias. The movement of the diaphragm would also open the switch allowing the diaphragm to return in the other direction thus closing the switch and causing the cycle to repeat. The life of such horns is limited by the life of a power source used in the horn, which, unfortunately, may not be satisfactory. Similarly, the decibel (dB) range for common electrical horns is limited to an initial response of about 90 dB based on the low current level available from conventional battery systems.
A need, therefore, exists for a portable electrical horn that has an increased power-source storage capacity, that has a simple structure allowing for a convenient storage and easy replacement of power sources, that has an extend useful shelf life without the detriments caused by leaks, and that is safely handled by all users including children and the unskilled without danger.
Still a further need exists for a portable electric horn providing for unmistakable indication of the end of the useful life of the current power source and automatic switching between the current power source and a spare one.